Good teaching makes a big difference in how much students learn, but researchers still don't know exactly why some teachers are better than others.
You could fill the back of a car with all the books and papers that prove how important teachers are, but education experts can't explain exactly what it is that effective teachers do to raise student achievement.
You tend to get two kinds of answers when you ask people, "What is a good teacher?"
Educators toss out phrases like "effective goal setting" and "maximizing instructional time". If you're not an education expert, you will quickly get bored or confused. People who don't talk in jargon typically answer the question with broad statements about inspiration, or they'll tell you about the teacher who changed their lives. After a while it all feels mushy and mystical and unknowable.
Harvard University professor Heather Hill is amazed that researchers don't know what makes a teacher effective. "People have yet to go into classrooms on a large scale and say, 'What is it?'" she says. "Is it that the teacher runs a tight ship and the kids are really able to profit because they're paying attention? Is it the way the content is presented to the kids? Is it the teacher's relationship with the kids and the fact that the kids are convinced the teacher has their best interests in mind? We don't really know at this point."
Hill is involved in a large study that may provide answers. It's called the Measures of Effective Teaching (MET) project. Researchers are observing 3,000 teachers in seven school districts across the country. They're gathering detailed information about what teachers are doing in their classrooms. Researchers will take that information and see how it correlates with changes in student test scores.
Looking at how test scores change while students are in a teacher's class is the way most researchers measure teacher quality now. The ultimate goal of the MET project is to come up with other ways to judge teaching. Hill says what researchers want – and schools need – are ways to define good teaching that go beyond "she raised the kids' test scores."
Researchers and teachers have theories and insights about what effective teaching looks like, gained from years of experience teaching or studying teachers. Here are some of the things they have learned: